The present invention relates to a suspension arrangement for suspending vibratory rams or other vibrating devices or bodies.
Vibratory rams are utilized for insertion or withdrawal of boards, posts, tubes, or other elements in construction of dams, canals, underground structures and the like. They are held by cables or iron carrying rings on a crane, a transverse, a frame, and the like. Vibrations which are developed during operation of the vibratory ram are transmitted in disturbing and disadvantageous manner more or less strongly to the cable system, the crane, the transverse and/or to other parts and locations. The resulting oscillating and striking action may be so strong that not only respective parts and bodies are subjected to high strains, but also considerable noise is produced with its detrimental action. These and other shortcomings and disadvantages always exist and are unavoidable when a vibratory ram is suspended and held by holding rings, hooks or other rigid members on a crane, a transverse, a frame or other parts. It has been shown that by suspending of the vibratory ram with the aid of conventional cables on a crane, a transverse, or a frame disadvantageous oscillations, impacts, strains, noise and other troubles cannot be prevented. The above-described suspension of the ram unavoidably negatively affects the transverse, the crane or the frame and causes oscillations and displacement of the same which leads, under some conditions, to damage and operational failures or even to breakage and destruction of one or several parts of the arrangement.
Vibratory rams are known which are provided with spiral pressure springs for dampening the oscillations. Such rams have a disadvantage that they are highly susceptible to damage and produce high noise. High dynamic force is developed during operation of these rams which result in unavoidable harmful contact and forced impact between individual convolutions of the spiral pressure spring. Guides which in this case are provided for the springs are complicated and contact with the spring with friction. The guides are unfavorable and disadvantageous inasmuch as they are subjected to high wear and high heating, especially in the conditions of frequencies in the region of natural resonance. Very disadvantageous is ineffectiveness of such pressure spring arrangement resulting from the fact that when the required pulling action is applied to the spring, the convolutions of the spring are pressed to each other so that the spring acts as a "block" and does not absorb undesirable oscillations.
It is also known to utilize a rubber block corresponding to a pulling head, instead of the spiral pressure spring. Arrangements with the spiral springs or with the rubber blocks must guarantee good dampening of oscillations in conditions of high tangential stresses with respective relatively high static prestressing. When a necessary great load is applied, the pulling head of the known arrangements must be located very high so that the arrangement has a disadvantageously abnormal height and very unfavorable total center of gravity for the vibratory rams. In these cases during operation there is a danger of damaging, breaking and/or failures of parts of the vibratory rams and/or of the rammer elements.